Currently, the most effective method for treatment of severe or nonhealing osseous defects is autogenic bone grafting, which involves the transplantation of bone from another part of a patient's body into the defect. Significant disadvantages are associated with autogenic bone grafting, including donor site morbidity and limited tissue availability. Bone banks have been established to provide an alternative source of bone grafting material, consisting of allogenic freeze-dried bone. Allogenic bone grafts, however, are very expensive and do not heal as well as do fresh autogenic bone grafts.
Attempts to overcome these problems have involved the use of calcium phosphates and apatites, as well as derivatives of natural bone to initiate new bone formation. Tricalcium phosphate and apatites have generally been employed to physically support the newly formed bone. Although such materials have been disclosed to be useful for dimensional augmentation after subperiosteal implantations, it is believed that they tend to exhibit slow or incomplete healing.
Demineralized, lyophilized bone has also been used as a component of osteoinductive agents. See, M. R. Urist, Science, 150, 893 (1965). Recently, M. R. Urist et al., in U.S. Pat. No. 4,294,753 and in Proc. Natl. Acad. Sci. USA, 76, 1828 (1979) have disclosed the use of proteins derived from such bone matrices with various carriers to induce new bone formation. However, it can be difficult to reproducibly prepare these materials, which must be characterized by various bioassay systems.
Therefore, a need exists for compositions which are useful to repair osseous defects by promoting the formation of new bone therein. A further need exists for compositions useful for osseous repair which can be prepared reproducibly, e.g., which incorporate well characterized components.